Mowing heights for finer-bladed zoysias typically range from 0.5–1.5 inches while wider-bladed zoysia mowing heights range from 1–2 inches. Depending on the type of zoysia you have, your lawn should typically be kept between 0.5–2 inches. During the fall, mowing will occur less often—keeping your zoysia slightly will encourage deeper root growth which helps it survive in colder temperatures and during winter dormancy.
Water less as temperatures drop—too much water will lead to disease. Water to prevent drought stress while grass is actively growing and after the beginning stages of dormancy to prevent dehydration.
Check for and control any white grubs. Treat with an insecticide if needed. If you use a granular variety, water the lawn immediately after application to help soil absorption.
If large patch is a common problem in your zoysia, apply a fungicide at a preventative rate. If you use a granular variety, water the lawn immediately after application to help soil absorption. Consider mapping those areas because fungicide treatment can be expensive.
If you have a mature, established zoysia grass lawn, drop your mower a notch and give your lawn a “buzz-cut” for the first mow of the spring with a rotary mower that has a sharpened blade. Bag up all the material to keep excess clippings from clumping or causing disease.
After your initial “buzz-cut,” begin mowing your zoysia grass at the desired height. Keep fine bladed zoysias mowed between 0.5–1.5 inches. Keep coarse bladed zoysia grass mowed between 1–2 inches. You can return to spreading your mower clippings on the lawn at this time.
Don’t overwater. Zoysia needs about 1 inch of water a week considering rainfall. If you apply any granular fertilizer or control product, you will need to water it in. This is a sufficient amount of water for the week. Overwatering may promote disease outbreak. Conduct an irrigation audit to evaluate how much water is being delivered to different areas of your lawn.
Apply a pre-emergent herbicide when soil temperatures reach 55 degrees Fahrenheit. This will prevent summer annual weeds like crabgrass and goosegrass from plaguing your lawn and garden. Apply post-emergent herbicides in May as needed to control summer annual and perennial broadleaf weeds like white clover, knotweed, spurge and lespedeza. Products containing multiple broadleaf active ingredients are more effective in controlling broadleaf weeds.
Apply a systemic fungicide at a preventive rate to keep disease from taking hold of your lawn. You may begin to see disease outbreaks as your zoysia begins to green up. Do not apply fertilizer until you’ve applied a systemic fungicide at a curative rate and your grass has recovered.
Zoysia mowing heights during the summer generally range from about 1–2 inches. Finer-bladed zoysias should be kept at a height of 0.5–1.5 inches. When mowing during the summer, never remove more than 1/3 of the leaf blade at a time. If you remove more than that, you will stress the grass and it may go brown for a short time. Taller blades provide more shade for your root system to stay cool and retain moisture during the hot summer days. If you are returning from vacation, you may have to mow multiple times to get the grass back to the desired height. Wait about 3–5 days between each mowing.
Do not overwater the grass. Zoysia grass only needs about 1 inch of water weekly. Water for longer periods of time, less frequently and in the early morning hours. Take rainfall into consideration.
Disease outbreaks in zoysia are uncommon at this time. Treat with a broad-spectrum fungicide like Heritage if needed. If you use a granular variety, water the lawn immediately after application to help soil absorption. Calculate that watering into your weekly watering amount.